Footwear with improved sole assembly

ABSTRACT

An article of footwear including an outer sole assembly and an upper, the outer sole assembly extending lengthwise from a rear end to a front end, and widthwise between a lateral side and a medial edge, the outer sole assembly having a surface for contact with the ground. The contact surface has a first strip, the first strip having an alternation of projections and recesses. The contact surface has a second strip, the second strip having an alternation of projections and recesses. The projections and recesses of the first strip are arranged alternately with respect to the projections and recesses of the second strip.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon French patent application No. 10/02985, filed Jul. 15, 2010, the disclosure of which is hereby incorporated by reference thereto in its entirety, and the priority of which is claimed under 35 U.S.C.§119.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an article of footwear, such as a shoe, in particular a shoe intended for the practice of a sport.

2. Background Information

Footwear of the aforementioned type can be used in disciplines such as walking, whether or not athletic, or running on flat or mountainous terrain, mountaineering, skateboarding, ball-playing sports, and the like.

An article of footwear, or shoe, can have a low upper or a high upper. The shoe can also be relatively flexible or, conversely, more rigid. However, the shoe, regardless of its general appearance or the activity performed, must meet the expectations of a user. First, the shoe should allow for an easy rolling movement of the foot, which means that on a flat ground, for example, the foot rolling movement should occur freely and evenly. This is to minimize the energy expenditure of the user with each foot rolling movement when walking or running. Second, the shoe must adhere sufficiently to the ground, which means that it should not slip undesirably, in the sense that it should enable a user to control the supporting forces, the impulses, or the transmission of sensory information between the ground and the foot.

The prior art has proposed a number of solutions seeking to achieve easy rolling movement and adequate adherence to the ground.

In particular, it is known to manufacture a shoe in which the outer sole assembly has a surface for contact with the ground which bears small projections. This structure enables the rolling movement to occur freely because the spaces between the projections enable the outer sole assembly to flex freely. In addition, the evenly distributed projections allow for a uniform rolling movement, on the one hand, and sufficient adherence to an even terrain. A shoe of this type is particularly suited for walking or running, for example, in a stadium. However, although this shoe combines a free and uniform rolling movement with sufficient ground adherence for a number of situations, the same is not true for all situations. Indeed, in certain situations, the adherence is insufficient. This is particularly true on rugged terrain, with obstacles such as rocks or the like, typically found in the mountains, in the countryside, or in forests. Indeed, in these situations, the contact surface between the sole assembly and the ground is too small to provide adequate adherence.

Other shoes exist, which are adapted to specific terrains.

U.S. Pat. No. 4,130,947, for example, discloses a shoe in which the contact surface of the outer sole assembly has a series of transverse grooves. These grooves have a substantial depth of several millimeters. This sole assembly promotes a grip on loose ground or snow. The grooves are adapted to increase the transverse rigidity and to facilitate the longitudinal flexibility. However, this shoe does not enable a completely free and uniform foot rolling movement. Indeed, the ability of the outer sole assembly to flex longitudinally, along a transverse axis, varies from one location to the next. Flexibility is substantial in the area of a groove, but is reduced between two grooves, which is due to variations in thickness of the sole assembly caused by the grooves. As a result, there is an alternation of hard and flexible zones in the area of the outer sole assembly. This alternation disrupts the rolling movement of the sole assembly, and therefore of the foot, by making it uneven. Moreover, a thick zone, comprised between two grooves, requires greater force to flex. Thus, the energy efficiency associated with walking or running is reduced. Also noteworthy is the risk of fatigue rupture of the thin zones in the area of the grooves.

None of the known shoes appear capable of combining the characteristics of free and uniform rolling movement of the sole assembly on the ground, sufficient adherence on flat terrain, and adherence or grip on uneven terrain. In other words, the prior art shoes are not versatile enough or are otherwise too application-specific.

SUMMARY

In view of the preceding, the invention generally improves upon prior art shoes. In particular, the invention combines in a single article of footwear, or shoe, the characteristics of free and uniform rolling movement of the sole assembly on the ground, sufficient adherence on flat terrain, and sufficient adherence or grip on uneven terrain. This means that the invention provides for a shoe that is more versatile and more efficient in all situations.

As described in more detail below, the invention provides the aforementioned versatility broadly, so that it is available whether on wet, damp or dirt terrains, or on more predictable terrains, such as dry terrains.

In addition, the invention provides damping capability in the area of the outer sole assembly. The invention optimizes the behavior of the sole assembly during the entire time, or at least a significant portion of the time, that it is in contact with the ground, depending upon the activity in which the wearer is engaged.

Further, the invention improves the accuracy in the transmission of sensory information or impulses associated with walking or running.

Still further, the invention minimizes the mass of the outer sole assembly as much as possible.

To this end, the invention provides a shoe, or article of footwear, including an outer sole assembly and an upper, the outer sole assembly extending lengthwise from a rear end to a front end, and widthwise between a lateral side and a medial side, the outer sole assembly having a surface of contact with the ground.

The contact surface of the shoe according to the invention includes first and second surface strips, hereafter referred to simply as strips, the first strip having an alternation of projections and recesses and the second strip having an alternation of projections and recesses, the projections and recesses of the first strip being arranged alternately with respect to the projections and recesses of the second strip.

It can also be said that the first strip includes a reference section that has a projection and a recess; that the second strip includes a reference section that has a projection and a recess; that the projection of the reference section of the first strip is next to the recess of the reference section of the second strip; and that the recess of the reference section of the first strip is next to the projection of the reference section of the second strip.

This structure organizes an alternation of projections and recesses in a direction parallel to the strips, as well as an alternation of projections and recesses in a direction perpendicular to the strips. It will be seen more clearly below that a strip corresponds to a subdivision of the contact surface, the strip being capable of being straight or curved and oriented along the longitudinal direction of the shoe or along another direction. The alternation mentioned hereinabove is provided in a subdivision of the contact surface which has the projections and the recesses according to the invention. It will be seen more clearly below that the contact surface can include a plurality of subdivisions, or can be entirely organized in this manner.

In a subdivision, the projections alternately contact flat ground, regardless of the direction in which the rolling movement of the outer sole assembly occurs. This means that if the outer sole assembly rolling movement occurs in the direction of the strips, a projection of the first strip contacts the ground, after that a projection of the second strip contacts the ground, after that another projection of the first strip contacts the ground, and so on. This occurs for all directions of rolling movement. As a result, the rolling movement of the outer sole assembly and, therefore, of the foot is uniform and free. The adherence to the ground is satisfactory because the switch from one projection to another, in terms of support, occurs evenly. It can also be said that there is continuity of contact between the sole assembly and the ground, when the first rolls on the second.

In the case of uneven terrain, of the mountainous type more or less covered with rocks, the ruggedness of the ground cooperates with the recesses. In fact, the ground asperities penetrate more or less into the recesses. There is an increased adherence in the area of the recesses, as they present a raised contact surface relative to the surface of the openings that they demarcate between the projections. In addition, the recesses create connections by obstacles between the ground asperities and the outer sole assembly. As a result, the adherence and/or the grip on uneven terrain is improved, compared to the adherence and grip obtained with shoes from the prior art. The same remains true on muddy ground, for the recesses act as large spikes, from which the mud comes out very easily.

Finally, in a shoe according to the invention, the outer sole assembly rolls evenly and freely on flat terrain, adheres sufficiently on the flat terrain, and also adheres or grips reversibly on uneven terrain. This means that the shoe of the invention is versatile and adheres to terrain that is even or uneven.

The shoe according to the invention provides a substantially improved grip compared to prior art shoes.

BRIEF DESCRIPTION OF DRAWINGS

Other characteristics and advantages of the invention will be better understood from the description that follows, with reference to the annexed drawings illustrating, by way of non-limiting embodiments, how the invention can be embodied, and in which:

FIG. 1 is a front perspective view of the bottom of a shoe according to a first embodiment of the invention,

FIG. 2 is a side view of the shoe according to FIG. 1;

FIG. 3 is a bottom view of the shoe according to FIG. 1;

FIG. 4 is a cross section along the strip IV-IV of FIG. 3;

FIG. 5 is a cross section along the strip V-V of FIG. 3;

FIG. 6 is a cross section along the strip VI-VI of FIG. 5;

FIG. 7 is a cross section along the strip VII-VII of FIG. 5;

FIG. 8 is a cross section similar to that of FIG. 4, of a second embodiment of the invention;

FIG. 9 is a cross section similar to that of FIG. 5, of the second embodiment of the invention;

FIG. 10 is similar to FIG. 1, of a third embodiment of the invention;

FIG. 11 is a front perspective view of the bottom of a shoe, according to a fourth embodiment of the invention; and

FIG. 12 is a bottom view of the shoe according to FIG. 11.

DETAILED DESCRIPTION

The first embodiment described hereafter relates more specifically to articles of footwear, or shoes, intended for walking or running on flat or uneven terrain. However, the invention applies to other fields, such as those mentioned hereinabove. Also, while the term “shoe” is used herein for convenience and without limitation, the invention being directed to articles of footwear in general and can include, e.g., those with high uppers, low uppers, and mid-uppers.

The first embodiment is described hereinafter with reference to FIGS. 1-7.

As shown in FIGS. 1-3, a walking shoe is adapted to receive the foot of a user.

Conventionally, the shoe 1 generally includes an outer sole assembly 2, which extends in a longitudinal direction L, between a rear end 3 and a front end 4, and along a transverse direction W, between a lateral side 5 and a medial side 6. The outer sole assembly 2 includes a rear portion, or heel 7, and a front portion 8. According to the first embodiment, the bottom assembly 2 is a single unitary piece, in the sense that the heel 7 and the front portion 8 are co-extensive. However, these portions 7, 8 can be separated and spaced apart.

Also, the shoe 1 includes an upper 9 arranged on the sole assembly. As shown, the upper 9 includes a lower portion 10 which is constructed and arranged to surround the foot, but is devoid of a high portion. However, the upper could be provided to also include a high portion, such as a portion that would cover the wearer's ankle. Alternatively, such high portion could be such as to have an upper edge at mid-ankle.

The upper 9 includes a lateral quarter 12, a medial quarter 13, and a tongue 14. The tongue 14 connects the quarters 12, 13 to one another in order to provide continuity to the upper 9. However, in an alternative embodiment, a tongue can be omitted. In such a case, the quarters 12, 13 can be separated, abutted, or superimposed/overlapped.

A tightening device, such as laces alternately extending between the two quarters, can be employed to tighten, and untighten, the upper 9. However, the shoe 1 could be devoid of a tightening device.

Regardless of the structure of the upper, the outer sole assembly 2 has a ground-contacting surface 20. In other words, the outer sole assembly 2 has a bottom side structured and arranged to face the ground when the wearer walks or runs. The surface 20 is structured and arranged to have surface strips (or simply “strips”) 21, 22, 23, 24, 25, which are two or more in number. A strip is a subdivision of the contact surface 20 (or bottom side of the outer sole) which has a greater length than width. It could be said that a strip is an elongated subdivision, but which, as will be seen hereafter, can have various shapes or various curvatures. In particular, a strip can be straight, like a rectangle, or curved (concave or convex), in the form of a capital letter, such as C or S, for example.

In a non-limiting manner, the contact surface 20 has at least one first strip 21 and at least one second strip 22. As seen hereafter, the contact surface 20 can have a third strip 23, a fourth strip 24, a fifth strip 25, or even more.

The first strip 21, for example, includes an alternation of projections 31, 32, 33, 34, 35, 36 and recesses 41, 42, 43, 44, 45 which follow one another alternately, between the front end 4 and the rear end 3 of the outer sole. In any case, the first strip 21 includes a reference section 47 which has a projection 32 and a recess 41. The projection 32 and the recess 41 of the reference section 47 are next to one another, in the sense that one follows the other along the strip 21, i.e., they are successive, i.e., consecutive. Reference is made to this section 47 to facilitate the description, because it is clearly visible in the drawing figures.

Similarly, the second strip 22, for example, includes an alternation of projections 51, 52, 53, 54, 55, 56, 57 and recesses 61, 62, 63, 64, 65, 66 which follow one another alternately, between the front end 4 and the rear end 3 of the sole. In any case, the second strip 22 includes a reference section 67 which has a projection 52 and a recess 62. The projection 52 and the recess 62 of the reference section 67 are next to one another, in the sense that one follows the other along the strip 22. Reference is made to this section 67 to facilitate the description, because it is clearly visible in the drawing figures.

According to the invention, the second strip 22 is contiguous to the first strip 21, the projection 32 of the reference section 47 of the first strip 21 is next to the recess 62 of the reference section 67 of the second strip 22, and the recess 41 of the reference section 47 of the first strip 21 is next to the projection 52 of the reference section 67 of the second strip 22.

In the area of the subdivision of the contact surface 20, which contains the reference sections 47, 67 of the first strip 21 and second strip 22, there is an alternation of projections and recesses in a direction parallel to the strips 21, 22, as well as an alternation of projections and recesses in a direction perpendicular to the strips 21, 22. In this subdivision, the outer sole assembly 2 has a uniform and free rolling movement on flat terrain, adheres adequately to this terrain, and also adheres or grips reversibly on uneven terrain. In the area of this subdivision at least, the shoe according to the invention is versatile.

According to the first illustrated embodiment, and in a non-limiting manner, the contact surface 20 has a third strip 23. This third strip 23, for example, includes an alternation of projections 71, 72, 73, 74, 75, 76 and recesses 81, 82, 83, 84, 85 which follow one another alternately, between the front end 4 and the rear end 3. The third strip 23 includes a reference section 87, which has a projection 72 and a recess 81. The projection 72 and the recess 81 of the reference section 87 are next to one another along the strip 23. Reference is made to this section 87 because it is clearly visible in the drawing figures.

In the context of the invention, the third strip 23 is contiguous to the second strip 22, the projection 52 of the reference section 67 of the second strip 22 is next to the recess 81 of the reference section 87 of the third strip 23, and the recess 62 of the reference section 67 of the second strip 22 is next to the projection 72 of the reference section 87 of the third strip 23.

In the area of the subdivision of the contact surface 20 which contains the reference sections 67, 87 of the second strip 22 and third strip 23, there is an alternation of projections and recesses in a direction parallel to the strips 22, 23, as well as an alternation of projections and recesses in a direction perpendicular to the strips 22, 23. In this subdivision, the outer sole assembly 2 has a uniform and free rolling movement on even terrain, adheres adequately to such even terrain, and also adheres or grips reversibly on uneven terrain. In the area of this subdivision, the shoe is versatile.

Still according to the first embodiment, the contact surface 20 includes exactly three strips 21, 22, 23, i.e., no more; no less. Therefore, the strips 21, 22, 23 extend over the entire contact surface 20. For example, the first strip 21 is lateral, the second strip 22 is central, and the third strip 23 is medial. This optimizes the ground adherence and rolling movement capabilities, in the sense that such capabilities are exerted throughout the contact face 20.

In this context of optimization, the first strip 21 includes a plurality of sections 47, the second strip 22 includes a plurality of sections 67 and the third strip 23 includes a plurality of sections 87.

By way of non-limiting example, the first embodiment provides the following organization: the first strip 21 has five recesses 41, 42, 43, 44, 45, the second strip 22 has six recesses 61, 62, 63, 64, 65, 66 and the third strip 23 has five recesses 81, 82, 83, 84, 85. Consequently, the first strip 21 has six projections 31, 32, 33, 34, 35, 36, the second strip 22 has seven projections 51, 52, 53, 54, 55, 56, 57, and the third strip 23 has six projections 71, 72, 73, 74, 75, 76. It is to be understood that the projections and the recesses are alternately distributed along each strip, and also alternately perpendicular to each strip. Thus, the projections and the recesses are distributed in a checkerboard pattern over the entire contact face 20.

The first strip 21, the second strip 22, and the third strip 23 are oriented along the length of the shoe 1, which is also the longitudinal direction L of the sole assembly 2. This orientation provides stability to the sole assembly 2 during natural foot rolling movement when walking or running in a forward direction.

Further, the recesses 41-45 of the first strip 21 are transversely aligned with the recesses 81-85, respectively, of the third strip, i.e., along the transverse direction W of the outer sole assembly 2. Consequently, the projections 31-36 of the first strip 21 are substantially transversely aligned with the projections 71-76, respectively, of the third strip 23. The result is great transverse stability in supporting the wearer on the ground, especially if the ground is flat. There is also a good transverse grip on rough terrain. Indeed, each recess of the central strip 22 is demarcated by a lateral projection and a medial projection of the lateral strip 21 and medial strip 23, respectively. Consequently, each recess 61-66 is a cavity of the sole assembly 2, open only in the area of the contact surface 20. Therefore, if a ground asperity, such as a projection of a rock, is inserted in a recess of the central strip 22, a transverse sliding of the outer sole assembly 2 is prevented at times by the lateral projection, and at times by the medial projection. In fact, each lateral or medial projection is a transverse stop. This makes the shoe 1 particularly efficient when running in the mountains, because the undesired loss of adherence, along a transverse direction, is at least rare, if not entirely avoided.

In terms of dimensions, it is provided, for example, that the width of the first strip 21 ranges between 5 and 30% of the width of the outer sole assembly 2, that the width of the second strip 22 ranges between 20 and 80% of the width of the sole assembly 2, and that the width of the third strip 23 ranges between 5 and 30% of the width of the sole assembly 2. As a result, the central strip 22 is generally selected to be larger than the lateral strip 21 and medial strip 23. A resulting advantage is to optimize the transverse grip on rough terrain.

Longitudinally, for the first embodiment, the length of each of the first strip 21, second strip 22, and third strip 23 ranges between 85 and 100% of the length of the outer sole assembly 2. This is still in the context of optimizing the adherence and rolling movement properties mentioned above. However, satisfactory results are experienced when the lengths of each of the first 21, second 22, and third 23 strips range between 50 and 100% of the length of the outer sole assembly 2.

In a non-limiting manner, the first 21 and third 23 strips are provided to extend one another, i.e., they are co-extensive, in the area of the rear end 3 and front end 4 via a rear bridge 93 and a front bridge 94, respectively. This means that the lateral strip 21 and the medial strip 23 extend one another, i.e., they are co-extensive, in the area of the rear end 3 and/or the front end 4. Finally, the lateral strip 21, the rear bridge 93, the medial strip 23, and the front bridge 94 form a peripheral belt of the contact surface 20. This belt contributes to making the rolling movement of the outer sole assembly 2 more uniform. It is also possible to provide only one bridge 93, 94 in the area of the rear end 3 or of the front end 4, or even to provide none.

The width of the first strip 21 is constant along its length, the width of the third strip 23 is also constant, and the width of the second strip 22 is variable. In fact, the second strip 22, or central strip, is generally wider in the front portion 8 than in the rear portion 7. This increases the transverse grip toward the front. A resulting advantage is great stability of the sole assembly 2 when being largely supported in the metatarsal zone of the foot, particularly on uneven terrain. Again, the shoe is very efficient in mountain races.

Still for the sake of efficiency, the outer sole assembly 2 is provided to be light and abrasion-resistant due to the contacts with the ground. In practice, the outer sole assembly 2 includes a wear layer 95 (see FIGS. 4-7, e.g.), adapted to contact the ground, and a connecting layer 96, which connects the wear layer 95 to the remainder of the shoe 1. It is to be understood that the wear layer 95 defines the contact surface 20. The wear layer 95 is for example comprised of rubber or any equivalent material. The connecting layer 96, according to the first embodiment and in a non-limiting manner, is a damping layer. Therefore, the layer 96 includes a low density synthetic material, such as an ethyl-vinyl-acetate (EVA) foam, or any equivalent.

Each of the layers 95, 96, in particular embodiments of the invention, extends along the entirety of the outer sole assembly 2. This provides adherence ability combined with damping ability to the entire contact surface 20.

The sole assembly 2 can include more than two layers and/or additional elements.

As can be understood from all FIGS. 1-7, according to the first embodiment, the outer sole assembly 2 includes a wear layer 95 whose thickness “t” is generally constant. This facilitates the manufacture and lightens the sole assembly 2 as much as possible.

The phrase “generally constant” means that the wear layer 95 has a constant thickness, in spite of small projections that are added to improve adherence on wet terrain. Indeed, the projections 31-36, 51-57, and 71-76 mostly have asperities that are all designated by the reference numeral 97. These asperities, which are V-shaped, for example, are small projections with a thickness ranging between 0.5 and 7 mm. Values particularly ranging between 1 and 3 mm yield good results.

Given that the asperities 97 are primarily adapted to cooperate with ground having an even surface, it is not necessary to fill their recesses. In other words, the recesses 41-45, 61-66, and 81-85 mostly have an even surface, or even a smooth surface. This makes sense because the recesses are adapted to cooperate with projections on uneven terrain.

Alternatively, most of the projections 31-36, 51-57, and 71-76 can be provided to have an even surface, i.e., a surface without the asperities 97. In such a case, the shoe 1 is very efficient on dry terrain, whether even or uneven.

Regardless of the asperities 97, according to the first embodiment the sole assembly 2 includes a wear layer 95 whose thickness t ranges between 0.5 and 5 mm, and values particularly ranging between 1 and 3 mm yield good results.

As can be understood more particularly with reference to FIGS. 4-7, along a transverse subdivision of the contact surface 20 having the width of a section, the apexes of the projections 32, 52, 53, 72 are in the same plane, i.e., they lie within a common plane. In more general terms, the respective apexes of all of the projections are within an even rolling surface of the contact surface 20. As a result, this enables a uniform rolling movement of the outer sole assembly 2 and of the foot.

Referring in particular to FIGS. 4 and 5, in a transverse direction, i.e., from the lateral edge 5 to the medial edge 6, the damping layer 96 is continuous. The wear layer 95 is split. More specifically, an independent subdivision of the wear layer 95 corresponds to each strip 21, 22, 23. This makes it possible to obtain a contact surface 20 in relief, even if the wear layer 95 is initially made flat. However, as seen more clearly hereafter, it is possible to mold the entire wear layer 95 into a single unitary piece.

As can be understood from FIGS. 1-7, and with particular reference to FIGS. 6 and 7, most of the recesses have a rounded shape. For example, the first recess 41 of the first strip 21 has a concave bottom 100 and convex walls 101, 102, the latter connecting the bottom 100 to the projections 31, 32 of the same strip. This facilitates the manufacture of the sole assembly 2, and also enables a better transition between the supports on rough terrain and the supports on flat or even terrain.

Other embodiments are described hereafter with reference to FIGS. 8-12. For reasons of convenience, the elements that are shared with the first embodiment are designated by the same reference numerals. Only the differences are highlighted.

First, it is the second embodiment which is shown in FIGS. 8 and 9. In fact, there are two transverse cross sections in the context of FIGS. 4 and 5. It is seen here that the wear layer 105 of the outer sole assembly 2 is continuous from the lateral side 5 to the medial side 6. This means that the entire wear layer 105 is a single unitary piece.

The third embodiment is shown with reference to FIG. 10. As shown in FIG. 1, the outer sole assembly 2 of the shoe 1 has a first strip 21, a second strip 22, and a third strip 23. This embodiment is specific in that one or more recesses 62-66 are split. For example, it is essentially the recesses 62-66 of the second strip 22 which are separated by thin walls, such as those designated by the reference numerals 111, 112 for the second recess 62 of the second strip 22. The walls 111, 112 may be elastic elements, adapted to exert an elastic return after a deformation of the sole assembly 2 due, for example, to the foot rolling movement. This arrangement makes it possible to accumulate the energy associated with the foot rolling movement and to restore it at the end of the rolling movement. The reset of the shoe, and there of the foot, is better.

The fourth embodiment is next described with reference to FIGS. 11 and 12. Although it still has a first strip 21, a second strip 22, and a third strip 23, the contact surface 20 also has a fourth strip 24, the fourth strip 24 having an alternation of projections 121-124 and recesses 131-133; and the contact surface 20 further has a fifth strip 25, the fifth strip 25 having an alternation of projections 141-145 and recesses 151-154, the projections and recesses of a given strip being arranged alternately relative to the projections and recesses of a neighboring strip. It is noted that the strips 21-25 are contiguous to one another.

The first strip 21, the second strip 22, the third strip 23, the fourth strip 24, and the fifth strip 25 are oriented along the length of the shoe. In this case, the first strip 21 is lateral, the second strip 22, third strip 23, and fourth strip 24 are central, and the fifth strip 25 is medial. In a non-limiting manner, the first strip 21 has four recesses 161-164, the second strip 22 has three recesses 171-173, the third strip 23 has four recesses 181-184, the fourth strip 24 has three recesses 131-133, and the fifth strip 25 has four recesses 151-154. Finally, the shoe 1 according to the fourth embodiment adopts the same philosophy as the other embodiments. In this sense, the shoe 1 is very versatile as has been explained above; however, because the number of recesses per strip is smaller, the shoe 1 is suited for mixed courses that involve a little more flat than hilly portions.

In any case, the invention is made from materials and using techniques of implementation known to the one with ordinary skill in the art.

The invention is not limited to the embodiments described hereinabove, and includes all technical equivalents that fall within the scope of the claims that follow.

In particular, the number of strips may vary. Depending upon the extent of a strip, various recesses can have various dimensions. Similarly, various projections can have various dimensions.

The recesses, or a number thereof, can be totally or only partially devoid of a wear layer.

In addition to the foregoing, the invention illustratively disclosed herein suitably may be practiced in the absence of any element which is not specifically disclosed herein. 

1. An article of footwear comprising: an outer sole assembly and an upper; the outer sole assembly extending lengthwise from a rear end to a front end and widthwise between a lateral side and a medial side; the outer sole assembly comprising a ground-contacting side; the ground-contacting side comprises: a first strip having an alternation of projections and recesses; a second strip having an alternation of projections and recesses; the projections and recesses of the first strip being arranged alternately with respect to the projections and recesses of the second strip.
 2. An article of footwear according to claim 1, wherein: the first strip includes a reference section having a projection and a recess; the second strip includes a reference section having a projection and a recess; the projection of the reference section of the first strip is next to the recess of the reference section of the second strip; the recess of the reference section of the first strip is next to the projection of the reference section of the second strip.
 3. An article of footwear according to claim 2, wherein: the ground-contacting side of the outer sole assembly includes a third strip; the third strip includes a reference section having a projection and a recess; the projection of the reference section of the second strip is next to the recess of the reference section of the third strip; the recess of the reference section of the second strip is next to the projection of the reference section of the third strip.
 4. An article of footwear according to claim 2, wherein: the first strip, the second strip, and the third strip are oriented along a length of the article of footwear.
 5. An article of footwear according to claim 3, wherein: the first strip is lateral; the second strip is central; the third strip is medial.
 6. An article of footwear according to claim 3, wherein: the first strip includes a plurality of sections; the second strip includes a plurality of sections; the third strip includes a plurality of sections.
 7. An article of footwear according to claim 3, wherein: the first strip has five recesses; the second strip has six recesses; the third strip has five recesses.
 8. An article of footwear according to claim 7, wherein: the recess of the first strip are transversely aligned with the respective ones of the recesses of the third strip.
 9. An article of footwear according to claim 3, wherein: the first strip has a width in a range of between 5% and 30% of a width of the sole assembly; the second strip has a width in a range of between 20% and 80% of the width of the sole assembly; the third strip has a width in a range of between 5% and 30% of the width of the sole assembly.
 10. An article of footwear according to claim 3, wherein: each of the first, second, and third strips has a length in a range between 50% and 100% of a length of the outer sole assembly.
 11. An article of footwear according to claim 3, wherein: the ground-contacting side of the outer sole assembly has a fourth strip; the fourth strip has an alternation of projections and recesses; the ground-contacting side of the outer sole assembly has a fifth strip; the fifth strip has an alternation of projections and recesses; the projections and recesses of each of the strips are arranged alternately with respect to the projections and recesses of a contiguous strip.
 12. An article of footwear according to claim 11, wherein; the first strip, the second strip, the third strip, the fourth strip, and the fifth strip are oriented along a length of the article of footwear.
 13. An article of footwear according to claim 12, wherein: the first strip is lateral; the second strip, the third strip, and the fourth strip are central; the fifth strip is medial.
 14. An article of footwear according to claim 11, wherein; the first strip has four recesses; the second strip has three recesses; the third strip has four recesses; the fourth strip has three recesses; the fifth strip has four recesses.
 15. An article of footwear according to claim 5, wherein: the lateral strip and the medial strip are co-extensive in an area of the rear end and/or in an area of the front end of the outer sole assembly.
 16. An article of footwear according to claim 1, wherein: substantially all of the projections have smooth surfaces.
 17. An article of footwear according to claim 1, wherein: substantially all of the projections have asperities.
 18. An article of footwear according claim 1, wherein: substantially all of the recesses have smooth surfaces.
 19. An article of footwear according to claim 1, wherein: one or more recesses are split.
 20. An article of footwear according to claim 4, wherein: along a transverse cross section along a width of the ground-contacting side of the outer sole assembly apexes of the projections are in a common plane.
 21. An article of footwear according to claim 4, wherein: respective apexes of all of the projections are within a uniform rolling surface of the ground-contacting surface of the outer sole assembly.
 22. An article of footwear according to claim 1, wherein: the outer sole assembly includes a wear layer having a thickness in a range between 0.5 mm and 5 mm.
 23. An article of footwear according to claim 1, wherein: the outer sole assembly includes a wear layer having a generally constant thickness.
 24. An article of footwear according to claim 1, wherein: a majority of the recesses have a rounded shape. 